uv4l-raspidisp.socket file ownership

[chadwallacehart]

Note from the UV4L author, Luca Risolia on uv4l-raspidisp.socket file ownership:

With regard to /tmp/uv4l-raspidisp.socket having root as owner, this
file is created by a program called raspidisp_server installed with the
uv4l-raspidisp-extras package. This program is automatically started by
the raspidisp_server.service, which is present in the same package, at
boot and runs in background as root.

raspidisp_server is a virtual keyboard: it open and listens to the
socket for a sequence of characters and emulates the corresponding key
strokes as if there were a real keyboard attached to the Rpi. For
example, by using the UV4L demo page with data channels enabled, if you
type 'a', 'b', 'c' there, then, assuming you have a terminal window open
on the rpi, you should see 'abc' appearing in it. It's useful for
controlling the rpi from a web page with the PC keyboard.

This video should make it clear:

https://www.youtube.com/watch?v=wthS8TPk2DE

For your purposes, I think it's enough to disable the systemd service
once for all (and reboot to get rid of any possible pending socket file
under /tmp/).